Cytological detection is the most commonly used technology of cell biology. The immunological staining detection method for suspended cells often uses the centrifugal technology to wash cells. The steps of the method include: obtaining a single suspended cell; fixing the cell or not; adding antibodies (or other substances can combine to the cell makers); washing off the unbonded antibodies by centrifugation; adding chromogenic substances; washing off the chromogenic substances by centrifugation; detecting staining conditions. Various detection modes and methods based on different antibodies or anti-antibodies basically repeat the operation steps described above thereby completing cell immunological staining and finally detecting the cell markers.
Conventional cell detection method is barely implementable for the cytomembrane markers detection. However, it becomes difficult when it comes to detection of intracellular markers such as cytoplasm and nucleus markers since the detection requires cytomembrane opening. Once the cytomembrane is opened, the osmotic pressure of cell will be changed thereby recovering cells by centrifugation beding difficult. Further, when the unbonded antibodies being washed of post cell staining, cells can not be tightly compressed to the bottom of the tube after centrifugation due to the change of cell osmotic pressure, thereby cells being removed during the supernatant removal. In most conditions, most cells are lost after the cell staining step is completed, therefore, the experimental results are incorrect or it is hard to complete the experiments. Hence, the immunological staining operation on suspended cells based on centrifugation is very difficult, which costs much time and effort but does not guarantee the result. Cell marker detection becomes more and more widely applied. The difficult operation of cell staining methods seriously blocks the applications of flow cytometer and other cell detection devices.